Rash on the back of my calf, itches and is spreading, it started real small like a bug bite, it has a ring shape with bumps, should i be rel concerned?

Could be ringworm: This sounds like what is commonly called ringworm, or tinea corporus. This is a common infection caused by a fungus. It is easily treated with Lamisil (terbinafine) or lotrimin, but make sure that this is what it is by going to your family doctor.

I would be concerned: You have to keep in mind the possibility of an infection - particularly of mrsa. If you don't see improvement - please see a doctor you may need an oral antibiotic.